Extract `model` module

1 files changed, 0 insertions, 382 deletions

diff --git a/src/eval/layout.rs b/src/eval/layout.rs
deleted file mode 100644
index 117c269a..00000000
--- a/src/eval/layout.rs
+++ /dev/null
@@ -1,382 +0,0 @@
-//! Layouting infrastructure.
-
-use std::any::Any;
-use std::fmt::{self, Debug, Formatter};
-use std::hash::Hash;
-use std::sync::Arc;
-
-use super::{Barrier, RawAlign, RawLength, Resolve, StyleChain};
-use crate::diag::TypResult;
-use crate::frame::{Element, Frame, Geometry};
-use crate::geom::{Align, Length, Paint, Point, Relative, Sides, Size, Spec, Stroke};
-use crate::library::graphics::MoveNode;
-use crate::library::layout::{AlignNode, PadNode};
-use crate::util::Prehashed;
-use crate::Context;
-
-/// A node that can be layouted into a sequence of regions.
-///
-/// Layout return one frame per used region alongside constraints that define
-/// whether the result is reusable in other regions.
-pub trait Layout: 'static {
-    /// Layout this node into the given regions, producing constrained frames.
-    fn layout(
-        &self,
-        ctx: &mut Context,
-        regions: &Regions,
-        styles: StyleChain,
-    ) -> TypResult<Vec<Arc<Frame>>>;
-
-    /// Convert to a packed node.
-    fn pack(self) -> LayoutNode
-    where
-        Self: Debug + Hash + Sized + Sync + Send + 'static,
-    {
-        LayoutNode::new(self)
-    }
-}
-
-/// A sequence of regions to layout into.
-#[derive(Debug, Clone, Hash)]
-pub struct Regions {
-    /// The (remaining) size of the first region.
-    pub first: Size,
-    /// The base size for relative sizing.
-    pub base: Size,
-    /// The height of followup regions. The width is the same for all regions.
-    pub backlog: Vec<Length>,
-    /// The height of the final region that is repeated once the backlog is
-    /// drained. The width is the same for all regions.
-    pub last: Option<Length>,
-    /// Whether nodes should expand to fill the regions instead of shrinking to
-    /// fit the content.
-    pub expand: Spec<bool>,
-}
-
-impl Regions {
-    /// Create a new region sequence with exactly one region.
-    pub fn one(size: Size, base: Size, expand: Spec<bool>) -> Self {
-        Self {
-            first: size,
-            base,
-            backlog: vec![],
-            last: None,
-            expand,
-        }
-    }
-
-    /// Create a new sequence of same-size regions that repeats indefinitely.
-    pub fn repeat(size: Size, base: Size, expand: Spec<bool>) -> Self {
-        Self {
-            first: size,
-            base,
-            backlog: vec![],
-            last: Some(size.y),
-            expand,
-        }
-    }
-
-    /// Create new regions where all sizes are mapped with `f`.
-    ///
-    /// Note that since all regions must have the same width, the width returned
-    /// by `f` is ignored for the backlog and the final region.
-    pub fn map<F>(&self, mut f: F) -> Self
-    where
-        F: FnMut(Size) -> Size,
-    {
-        let x = self.first.x;
-        Self {
-            first: f(self.first),
-            base: f(self.base),
-            backlog: self.backlog.iter().map(|&y| f(Size::new(x, y)).y).collect(),
-            last: self.last.map(|y| f(Size::new(x, y)).y),
-            expand: self.expand,
-        }
-    }
-
-    /// Whether the first region is full and a region break is called for.
-    pub fn is_full(&self) -> bool {
-        Length::zero().fits(self.first.y) && !self.in_last()
-    }
-
-    /// Whether the first region is the last usable region.
-    ///
-    /// If this is true, calling `next()` will have no effect.
-    pub fn in_last(&self) -> bool {
-        self.backlog.len() == 0 && self.last.map_or(true, |height| self.first.y == height)
-    }
-
-    /// Advance to the next region if there is any.
-    pub fn next(&mut self) {
-        if let Some(height) = (!self.backlog.is_empty())
-            .then(|| self.backlog.remove(0))
-            .or(self.last)
-        {
-            self.first.y = height;
-            self.base.y = height;
-        }
-    }
-
-    /// An iterator that returns the sizes of the first and all following
-    /// regions, equivalently to what would be produced by calling
-    /// [`next()`](Self::next) repeatedly until all regions are exhausted.
-    /// This iterater may be infinite.
-    pub fn iter(&self) -> impl Iterator<Item = Size> + '_ {
-        let first = std::iter::once(self.first);
-        let backlog = self.backlog.iter();
-        let last = self.last.iter().cycle();
-        first.chain(backlog.chain(last).map(|&h| Size::new(self.first.x, h)))
-    }
-}
-
-/// A type-erased layouting node with a precomputed hash.
-#[derive(Clone, Hash)]
-pub struct LayoutNode(Arc<Prehashed<dyn Bounds>>);
-
-impl LayoutNode {
-    /// Pack any layoutable node.
-    pub fn new<T>(node: T) -> Self
-    where
-        T: Layout + Debug + Hash + Sync + Send + 'static,
-    {
-        Self(Arc::new(Prehashed::new(node)))
-    }
-
-    /// Check whether the contained node is a specific layout node.
-    pub fn is<T: 'static>(&self) -> bool {
-        (**self.0).as_any().is::<T>()
-    }
-
-    /// A barrier for the node.
-    pub fn barrier(&self) -> Barrier {
-        (**self.0).barrier()
-    }
-
-    /// Try to downcast to a specific layout node.
-    pub fn downcast<T>(&self) -> Option<&T>
-    where
-        T: Layout + Debug + Hash + 'static,
-    {
-        (**self.0).as_any().downcast_ref()
-    }
-
-    /// Force a size for this node.
-    pub fn sized(self, sizing: Spec<Option<Relative<RawLength>>>) -> Self {
-        if sizing.any(Option::is_some) {
-            SizedNode { sizing, child: self }.pack()
-        } else {
-            self
-        }
-    }
-
-    /// Fill the frames resulting from a node.
-    pub fn filled(self, fill: Paint) -> Self {
-        FillNode { fill, child: self }.pack()
-    }
-
-    /// Stroke the frames resulting from a node.
-    pub fn stroked(self, stroke: Stroke) -> Self {
-        StrokeNode { stroke, child: self }.pack()
-    }
-
-    /// Set alignments for this node.
-    pub fn aligned(self, aligns: Spec<Option<RawAlign>>) -> Self {
-        if aligns.any(Option::is_some) {
-            AlignNode { aligns, child: self }.pack()
-        } else {
-            self
-        }
-    }
-
-    /// Pad this node at the sides.
-    pub fn padded(self, padding: Sides<Relative<RawLength>>) -> Self {
-        if !padding.left.is_zero()
-            || !padding.top.is_zero()
-            || !padding.right.is_zero()
-            || !padding.bottom.is_zero()
-        {
-            PadNode { padding, child: self }.pack()
-        } else {
-            self
-        }
-    }
-
-    /// Transform this node's contents without affecting layout.
-    pub fn moved(self, delta: Spec<Relative<RawLength>>) -> Self {
-        if delta.any(|r| !r.is_zero()) {
-            MoveNode { delta, child: self }.pack()
-        } else {
-            self
-        }
-    }
-}
-
-impl Layout for LayoutNode {
-    fn layout(
-        &self,
-        ctx: &mut Context,
-        regions: &Regions,
-        styles: StyleChain,
-    ) -> TypResult<Vec<Arc<Frame>>> {
-        ctx.query((self, regions, styles), |ctx, (node, regions, styles)| {
-            node.0.layout(ctx, regions, node.barrier().chain(&styles))
-        })
-        .clone()
-    }
-
-    fn pack(self) -> LayoutNode {
-        self
-    }
-}
-
-impl Default for LayoutNode {
-    fn default() -> Self {
-        EmptyNode.pack()
-    }
-}
-
-impl Debug for LayoutNode {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        self.0.fmt(f)
-    }
-}
-
-impl PartialEq for LayoutNode {
-    fn eq(&self, other: &Self) -> bool {
-        self.0.eq(&other.0)
-    }
-}
-
-trait Bounds: Layout + Debug + Sync + Send + 'static {
-    fn as_any(&self) -> &dyn Any;
-    fn barrier(&self) -> Barrier;
-}
-
-impl<T> Bounds for T
-where
-    T: Layout + Debug + Hash + Sync + Send + 'static,
-{
-    fn as_any(&self) -> &dyn Any {
-        self
-    }
-
-    fn barrier(&self) -> Barrier {
-        Barrier::new::<T>()
-    }
-}
-
-/// A layout node that produces an empty frame.
-///
-/// The packed version of this is returned by [`PackedNode::default`].
-#[derive(Debug, Hash)]
-struct EmptyNode;
-
-impl Layout for EmptyNode {
-    fn layout(
-        &self,
-        _: &mut Context,
-        regions: &Regions,
-        _: StyleChain,
-    ) -> TypResult<Vec<Arc<Frame>>> {
-        Ok(vec![Arc::new(Frame::new(
-            regions.expand.select(regions.first, Size::zero()),
-        ))])
-    }
-}
-
-/// Fix the size of a node.
-#[derive(Debug, Hash)]
-struct SizedNode {
-    /// How to size the node horizontally and vertically.
-    sizing: Spec<Option<Relative<RawLength>>>,
-    /// The node to be sized.
-    child: LayoutNode,
-}
-
-impl Layout for SizedNode {
-    fn layout(
-        &self,
-        ctx: &mut Context,
-        regions: &Regions,
-        styles: StyleChain,
-    ) -> TypResult<Vec<Arc<Frame>>> {
-        // The "pod" is the region into which the child will be layouted.
-        let pod = {
-            // Resolve the sizing to a concrete size.
-            let size = self
-                .sizing
-                .resolve(styles)
-                .zip(regions.base)
-                .map(|(s, b)| s.map(|v| v.relative_to(b)))
-                .unwrap_or(regions.first);
-
-            // Select the appropriate base and expansion for the child depending
-            // on whether it is automatically or relatively sized.
-            let is_auto = self.sizing.map_is_none();
-            let base = is_auto.select(regions.base, size);
-            let expand = regions.expand | !is_auto;
-
-            Regions::one(size, base, expand)
-        };
-
-        // Layout the child.
-        let mut frames = self.child.layout(ctx, &pod, styles)?;
-
-        // Ensure frame size matches regions size if expansion is on.
-        let frame = &mut frames[0];
-        let target = regions.expand.select(regions.first, frame.size);
-        Arc::make_mut(frame).resize(target, Align::LEFT_TOP);
-
-        Ok(frames)
-    }
-}
-
-/// Fill the frames resulting from a node.
-#[derive(Debug, Hash)]
-struct FillNode {
-    /// How to fill the frames resulting from the `child`.
-    fill: Paint,
-    /// The node to fill.
-    child: LayoutNode,
-}
-
-impl Layout for FillNode {
-    fn layout(
-        &self,
-        ctx: &mut Context,
-        regions: &Regions,
-        styles: StyleChain,
-    ) -> TypResult<Vec<Arc<Frame>>> {
-        let mut frames = self.child.layout(ctx, regions, styles)?;
-        for frame in &mut frames {
-            let shape = Geometry::Rect(frame.size).filled(self.fill);
-            Arc::make_mut(frame).prepend(Point::zero(), Element::Shape(shape));
-        }
-        Ok(frames)
-    }
-}
-
-/// Stroke the frames resulting from a node.
-#[derive(Debug, Hash)]
-struct StrokeNode {
-    /// How to stroke the frames resulting from the `child`.
-    stroke: Stroke,
-    /// The node to stroke.
-    child: LayoutNode,
-}
-
-impl Layout for StrokeNode {
-    fn layout(
-        &self,
-        ctx: &mut Context,
-        regions: &Regions,
-        styles: StyleChain,
-    ) -> TypResult<Vec<Arc<Frame>>> {
-        let mut frames = self.child.layout(ctx, regions, styles)?;
-        for frame in &mut frames {
-            let shape = Geometry::Rect(frame.size).stroked(self.stroke);
-            Arc::make_mut(frame).prepend(Point::zero(), Element::Shape(shape));
-        }
-        Ok(frames)
-    }
-}